The Third Child: Redemption
by Amaterasu Verdana
Summary: 6 months after the events of The Third Child. Ammy decided to settle down and live in the universe of Undertale. But when she brings back someone who didn't want to be returned, they leave once more. Then, a dark force returns once more. But their motives are strange. Suspicious, Sans and Gaster begin to search for answers. Will the dark secrets of the past finally be revealed?
1. 3-Sentence Prologues

The Third Child: Redemption

Their feet crunched through the snow as they ran, ran from their mysterious pursuer. " _Have to.. Keep going…. Can't let them….catch me...huff.."_ they thought. They were too caught up in their thoughts to notice the branch looming in front of them. Whack! Their head struck the branch. They collapsed.

Gaster walked up the path to Ammy's house, noticing the SAVE point Ammy put there. _"Clever,"_ he thought. He walked up to the door and knocked. He heard a yell from out back. "Come in the back!" And thus he did. Opening the back gate, he walked into a beautiful garden. In the center stood a giant cherry blossom tree. Surrounding the tree was a moat-style koi pond bordered with rocks. Ammy stood on the other side, caring to some plants. He noticed wolfsbane, chamomile, the golden flowers, and an assortment of bonsai. She had cleverly trimmed each bonsai in the shape of wingding symbols. Gaster, being Gaster, got the subtle pun. Viewed side-by-side, the trees spelled the message "bonsai garden". He always chuckled at this. "So, what are you doing, Ammy?"

"Oh, I was just planting some oregano. What's up?"

"I noticed a strange force in the rifts. Could that be a result of Chara falling in?"

"Hmm. Well, I can go in, if you want.."

"Oh, you don't need to! I was just speculating."

"Well, I'll check it out. Thanks for telling me."

Gaster excused himself and walked back home to the palace. He noticed Asgore was playing chess with Flowey. And Flowey actually seemed to be **enjoying** it. He walked in the main door, heading straight up the right-center staircase to the third floor. He then went to the first room on the left. "Sans, are you in here?"

"Yeah, dad. Come in."

"What are you doing?"

"I was sleeping."

"Really? Sigh. Sans, Ammy's UFC fight is tonight. You want to come?"

"Sure. It's the championship bout."

Later…..

" **In this corner, 130 pounds, 15 wins, 0 losses, fighting out of Lumeo, Canada, Amaterasu "Crimson Fang" Sakurai!"** Bruce Buffer announced. Ammy was wearing a cami and athletic shorts. She smiled. " **And in this corner, 135 pounds, 19 wins, 5 losses, Holder of the Bantamweight Championship Belt, fighting out of Kansas City, Kansas, Kaylin "Drill Sergeant" Jones!"** Kaylin smiled for the audience. " **Begin!** "

Kaylin took the first shot, but Ammy ducked the punch and round-kicked Kaylin in the liver. Kaylin recoiled, then countered with a nasty punch to the cheek. It connected. Kaylin kept punching, until Ammy countered with a left hook to the face, then a left elbow to the stomach. Ammy stepped back. Kaylin did the same. They both circled, until Kaylin punched to the head. Ammy swiftly sidestepped the strike,left-elbowing twice straight to the gut, then a right hook to the face. Kaylin went down, and Ammy kept punching, until the ref stopped it. " **The winner, by TKO, Amaterasu Sakurai!"** " _Aaaand the crowd goes wild,"_ Ammy thought.

Later….

Ammy walked in her house, walking along the outside corridors until she came upon a set of doors patterned with Japanese symbols. To the right of the door hung a sign with more Japanese symbols etched unto it. She opened the doors and walked in. A crossroads was there. She continued to go forward until she stopped at a room filled with books. She searched the third shelf and stopped at one book. She pulled it out and looked at the photos. " _Father…"_ she thought. A single tear ran down her cheek.

"Sans, can I visit Ammy's house?" Frisk signed.

Sans replied, "Ok. But I'm going with you, because I actually was going to."

Frisk replied, "Okay!"

And thus they went. Gaster heard them leaving, but he looked forward once again, picked up the cup, took a drink, set it down, and went back to work.

"Ammy? You in here?" Sans shouted, knocking on the door.

No response. They waited at the door for a few minutes before knocking again. Still no response. They decide to open the door. Sans sees that the brush door is open, and decides to walk through, opening the side doors one-by-one. Still, Ammy isn't in there. They walk forward, finding Ammy in the record room. They saw her standing there holding the old book. Ammy closed the book and put it back on the shelf. She turned slowly, startled by Sans and Frisk standing there. She stepped back, into the shelf. The shelf fell on her. She fell with a startled yelp. She eased it back up, careful not to damage any of the books. "Sans, Frisk, why did you do that?"

"What? We just came to visit." Sans said.

"Well, next time don't stand there silently."

"We were waiting for you to finish."

Later, after they fixed the shelf and Frisk and Sans went home…

 _Writer's Note: This scene was inspired by the Mann v. Machine Trailer for Team Fortress 2._

Sans lay on his bed asleep. Gaster sat at his computer, still typing. Toriel put ingredients together to make a pie. Frisk played with their toys. Papyrus read a book. Ammy watered plants. Flowey and Asgore played another game of chess. Mettaton posed dramatically. A quiet breeze flowed through Lumeo. Gaster glanced at the clock. _8:23._ He hit command-s on the keyboard and closed his document. He scooted out of his chair and stood up. He then walked out of his room and walked outside. He went to Sans's room. Sans opened his eyes and got out of bed. They walked to Toriel's room. She glanced at the clock, and lit a pleasant fire under the baking pie. They walked down and met with Asgore and Flowey. Asgore and Flowey both joined them without a word. They went to Mettaton's. He walked down and joined them. Undyne and Alphys both walked down the street. Everyone gathered. They all walked to Ammy's. But Ammy was already there. Everyone went to the secret spring. They prepared to have their little secret meeting. But then the springwater turned red. Chara rose out of the water. She had reverted to her normal form. **"Surprise! Not dead."**

Everyone gasped. Except Ammy. She just looked unimpressed. But then a reset button appeared. Chara pressed it. Nothing happened. She pressed it again and again. But every time, nothing happened. **"What!? HOW!? What did you do!?"**

"Heh heh. Because I changed the storyline, you can't reset." Ammy said.

" **Grrrr...Well, I'll just have to settle for** _ **killing**_ **you!"**

"Yeah...no." Ammy simply pulled out the paintbrush.

" **You think a measly paintbrush can stop** _ **me**_ **?"**

"Yeah, actually, I do." Ammy killed Chara with one stroke of the brush.

"Ammy, how did you do that?" Sans asked.

"This paintbrush is none other than the Celestial Brush."

"Woah.." Alphys said, her eyes gleaming.

The next morning…

Gaster and Sans were at the gym, practicing their magic. Papyrus was there too. Undyne was doing laps in the pool. Alphys was at the lab working on Mettaton, who had requested an upgrade to his battery life. Ammy was helping Frisk do their homework, and Toriel was out shopping. Nicecream guy and Burgerpants were walking down the sidewalk, talking. Mettaton had left his robotic body and was spending time with Napstablook.

Flowey was playing Solitaire. He drew 3 and put the 9 of spades on the 10 of hearts, then put the Queen of Clubs on the King of Hearts. From there he drew and put the Ace of Hearts up. Then he put the 2 of spades on the Ace of Spades. He played some more, and eventually he won.

Now to Gaster and Sans..

They weaved back and forth, practicing fighting. The unique walls of the private training room absorbed all attacks. Sans summoned a Gaster Blaster and shot it where Gaster was going. Gaster summoned a Gaster Blaster to block the attack. That Gaster Blaster then fired. Sans blocked it with a spinning bone. Gaster summoned his extra hands. The yellow hand fired. Sans shot bones, then took a bone and tried to strike the yellow hand, but the green hand reached out and shielded the yellow hand. Sans put a BLUE effect on Gaster's soul, keeping him grounded. The light-blue hand summoned blue bones. Sans stopped. The bones went through. The orange hand cast white dots to either side of Sans. He teleported before the hand set them to orange. The now-orange dots exploded. More appeared where Sans teleported to, and he grabbed one. Sans teleported to the orange hand and tossed the dot up in the air. The orange one set the dots to orange, and thus the hand was destroyed. Gaster looked irritated. The green hand cast a GREEN barrier around Sans. But Sans stretched out the barrier with bones and thus destroyed the GREEN effect. Gaster said, "Sans, you've destroyed two of my extra hands. We should stop for today."

"Yeah, you're right. Let's go check on Undyne and Papyrus."

And thus they did. Undyne and Papyrus were bench-pressing when Sans and Gaster walked up. "C'mon, Papyrus! You can't stop at 26! I know you can get to 30!" Undyne said.

"Hey, Undyne. You've been training Paps well, I see." Sans said nonchalantly.

"Yep! I made him do 100 squats, 100 push-ups, 100 sit-ups, and now he's doing 30 bench-presses with two 10-lb. Weights! Heheheheheheh!"

Papyrus finally finished doing 30 bench-presses. He laid down the bar gently, then rose and got off the bench. "I'm finished! Nyeh heh heh!"

And thus they all went home.

 _Notes: +The gym was made with the purpose of use by both humans and monsters._

 _+The rep Undyne made Papyrus do was called Undyne's Champion's Workout Jr. Once someone does that rep for a week, they move onto Undyne's Champion's Workout for a week(which is double the_ _ **everything**_ _). Then, they do Undyne's Champion's Workout Supreme, which is double that. So, the Supreme Workout is_ _ **four times**_ _the Jr. Workout!_

 _+The Sans and Gaster fight is based off of Camila Cuevlas video,_ _Yet Darker._

 _+Celestial Brush is from Okami_

 _+Many references are hidden throughout all the chapters. This chapter was comprised of Camila Cuevlas' art, Okami, TFS DBZA, Obscure Undertale Ships, TF2, UFC, and the super-easy art of 3-sentence prologues._

 _+The first paragraph is the prologue. The rest is all Chapter 1._


	2. Overdue Exposition

Gaster jolted out of bed. He glanced at his alarm clock. _4:30._ He got out of bed, still halfway asleep. He got ready for work and walked out of his room, surprised to see Sans standing there, holding two cups of coffee. He handed one to Gaster and said, "So, you ready to head out?"

"Yes, although there is still one problem."

"What is it?"

Suddenly knife. Chara was there. " **Who knew that I can't be killed! This will be way more interesting now!"**

"Why does this keep happening!" Sans shouted. Bad move. Toriel's door opened. Toriel's head popped out, saw what was happening, made a face, and slowly moved her head back and slowly closed the door. Papyrus and Frisk seemed to have not been woken up by the shout.

Suddenly Ammy. She had teleported here. She just stood there and said, "Wow. You're **soooooo** strong! Not. Why can't you just die? I've killed you already, you shouldn't be cheating death! Unless, that is,..."

"You just won't die because you're soulless."

Gaster jolted out of bed. For real. " _Just a dream,"_ he thought, getting out of the bed, and glanced at the alarm clock. _4:35._ He dressed himself and walked out the door. Sans was standing there, holding two cups of coffee. "Are you getting a sense of deja vu?" Sans said.

"Yes, I think the world reset. But I thought it couldn't, because of Ammy?"

"I don't know, but let's leave the matter alone. I got you some coffee. Iced-cappuccino, right?"

"Yes. Now, let's head to work, shall we?"

And thus they did. (Gee, I do use this sentence way too often, don't I?)

Three hours had passed. Alphys had been working on the DT extraction machine, which she was still using to experiment with DT. But, now she had access to an almost unlimited source; the human population. She had figured out a way to perform this process without harming the human. She typed her success into the computer's log program. " _Entry Number 24. The DT Ex. machine can now extract DT w/o harming a human in the process. Huge success!"_

 _Entry Number 18: Sans and I both worked together to develop a new version of the CORE to create a source of nearly unlimited power. We have found an underwater volcano in a small deep-ocean trench about 50 kilometres off of Kiwi Island, a small isle just a short distance off the coastline. However, the obvious roadblock is the ocean. We may have difficulties reaching the site. At least we will have no trouble extracting geothermal energy from the volcano's center. We can just replicate the device inside the original CORE. Which, I might add, is still functioning._

Ammy worked to one side, focusing on her own project. When Gaster questioned her one day about it, she replied, "It's a gateway device. However, it's not portable. I was thinking we could place several devices throughout the New CORE facility once it is complete. Then, we could establish a network of devices to reach the new facility. And maybe solve that problem."

Mettaton was going on tour. Alphys had, in the meantime between chapters, finished upgrading him. He now had his NEO form removed, and extended battery life on his EX form. He had quickly gained popularity, and none thought that there was anything wrong with his style. Until the narrow-minded humans came. They tried to get rid of every monster tradition, but a fleet of Canadian cavalry officers drove the violent protesters off. The monsters took advantage of the situation, forming the Lumeo Defense Force, an intimidating squadron comprised of both humans and monsters.

Ammy walked home from work, going through the daily habit of SAVING as she walked up the path. She walked to the left, towards the conveniently-placed hot spring. She instead opened up a hidden panel to the left, covered in grass. She glanced around, then hopped down the hole, closing it behind her. She climbed down the ladder, coming to the first floor. Said first floor was the relatively normal cellar. She had one wall covered in barrels of aging sake. She instead pressed down several bricks along the wall near the door. A segment of the floor to the left drew back, revealing a spiral staircase. She walked down it, flipping on a simple light switch. Around a quarter-mile of laboratory rooms below were lit up. She walked down, heading to the room with the gateway portal. "At least I got an excuse to work on one at the lab," she said, flipping on a seperate light switch. The room was illuminated. She looked at the sliding switch located next to it, and pushed it to the middle. The room was bathed in green light. Ammy walked forward, coming to a control panel filled with buttons, keypads, switches and levers. She entered a sequence into said panel, and the gateway suddenly jolted on with a spark. The screen in front of her suddenly flashed red, and showed, " **WARNING! WARNING! MAGICAL SURGE CONTAINMENT: 20%. BREACHED: 80%. REQUIRES IMMEDIATE ATTENTION."**

Ammy rapidly punched multiple sequences into the control panel, which seemed to contain the surge. A figure emerged from the gateway. The figure was revealed to be…

Asriel. He looked at the surroundings, then said, "I didn't want to be brought back this way. Return me to my flower form, I am not stable." He then walked back into the portal, after a nod from Ammy. Suddenly, Chara rose once again. She was once again human. **"So, you can bring back the lost. And I sensed Asriel return to this world. However, I've realized my mistakes. Do you forgive me?"**

"I have reason not to trust you, but I will put that aside. But, do you still want to return Asriel?"

 **"Yes, but if he does not want to return, how do we return him?"**

"Flowey."

The next morning, Sans awoke to the sound of his alarm clock. It was Saturday, his day off. He stepped outside his door only to find Ammy there. Ammy said, "Hey Sans. Would you mind helping me out?"

"Sure. What is it?"

"I need you to test the new gateway device."

"Okay."

They teleported to the lab, to Ammy's corner. She said, "I set up the other one at the New CORE site platform so we can supervise. All you have to do is walk in it when I activate it with the control panel."

She walked over to the panel and pressed a button on the panel. A screen extended out of the top of the panel, showing a rough map of the Lumeo area and the ocean to the east. She touched the glowing dot out in the ocean, and the gateway roared to life. It was filled with a swirl of blue and red. Sans noticed a chart on the panel, showing distinctive dots of colors that corresponded to text. He guessed that the text signified a location that corresponded with the color of the gateway. He walked into the gateway, and was transported instantly. He noticed that the platform was created using girders and stone. The gateway was in a small room with the gateway placed near the wall, yet some distance away for safety. He walked back through the gate, emerging back through in the lab. Ammy leaned over the computer screens, a grin spreading across her face. "Haha! Success! It worked!" She said, standing up and shutting off the gateway. They teleported back, and Ammy teleported home.

Later, at the New Palace, Asgore, Toriel, Sans, Papyrus, Frisk, Alphys, Gaster, Undyne, and Ammy all ate dinner at the table. They were celebrating the scientific achievements of the last 2 weeks, and everyone feasted. Okay, out with the filler! Plot time!

After the feast, Ammy returned home. She went down back to her secret lab, where Chara waited in the chemistry room. As Ammy walked in, she went over to the desk and opened the Stickies app, looking at her notes. "Chara, how much do you know about chemistry?"

" **Not that much."**

After one simple lesson…

"So, which is the purer metal, copper or iron?"

" **Iron."**

"Correct. Well, that was rather uneventful." She typed something on the sticky.

Time passed, and science stuff was conducted by a scientist and a former murderer. Later that night, around 10:00...

Sans and Gaster walked up the path to Ammy's house, noticing that Ammy was strangely absent. He stopped and said, "Wait. There's a strange energy coming from next to the hot spring." They walked up to it.

Gaster said, "Strange. There must be a panel." They opened it, noticing that it was hidden. "Strange. Ammy did this, so what's it for?"

"I don't know, but why would she hide the panel to her cellar?"

"Hmm. Wait, the dust on some of these bricks is wiped away in some places. Let's push them." Gaster pushed said bricks.

The staircase opened to the left, and they went down. They stopped at the window, and looked at the lit rooms. A figure was sitting in one of the rooms. They walked down, and navigated through the rooms until they reached the room the figure was in. It was Ammy, and she was sitting at a desk, typing on a computer. The room appeared to be a chemistry lab. She must have heard them come in, turning around. She said, "Back so soon, Ch-" She stopped when she saw Sans and Gaster in the doorway. "What are you doing here?" She asked, an accusatory tone in her voice.

"We came to see you. What is this, Ammy? Why do you have a huge underground lab?"

"You…. don't wanna know."

"Tell us."

"Okay, but get ready for a long story."

 _Notes:+The "reset" at the beginning of the chapter will actually be touched upon in later chapters._

 _+Kiwi Island_ _ **is**_ _shaped like a Kiwi._ _ **Biiiiiig surprise.**_

 _+Ammy's sticky notes are typed in WIngdings and Comic Sans as a homage to her colleagues._

 _+A prologue to the series is going to be posted on my tumblr._

 _+Chara being "human" is her original form when she first fell into the underground._

 _+Writing filler content can either be fun or tedious._

 _+Ammy can SAVE._

 _+Ammy recommends at least three people when operating the gateways. One on each control panel, and one going through._

 _+Yes, the platform looks like an oil rig. Get over it._

 _+The new facility is called the New CORE. Thanks, Gaster._

 _+Frisk takes special classes at the school, and takes a special Health class for you-know._

 _+Asgore trimmed the hedges into each of the boss monsters' likenesses._

 _+One day, Ammy bought a huge brick of granite. The next day, the Royal Fountain now had a new centrepiece. It was Asriel with the seven human souls. It is now a wishing fountain._

 _+There are 5 religious buildings in Lumeo: a catholic church, a mosque, whatever the Jewish version of a church is; a miscellaneous building which can also be used for many other purposes; and the Annoying Dog's home._

 _+Yes. Ammy built_ _ **everything**_ _in her lab. Except the equipment. But she did build the gateway._

 _+Ammy also owns a rice farm and a mill. It's near the river. And what did I name the river? The River Chad. Yes, the RIver Chad._

 _+There is actually a network of creeks and streams throughout the Lumeo area. And the River Chad runs through the entire town._

 _+Undyne and Alphys's house is on top of a hill._

 _+Ammy's sake is well-known for it's quality and variety._

 _+Because none of the monsters need to use the restroom, none of the houses contain bathrooms with toilets. Because of this, public restrooms were built throughout the town for the human residents. Although Ammy's does have one…_


End file.
